US3772059A - Method for producing microporous sheet material - Google Patents

Method for producing microporous sheet material Download PDF

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US3772059A
US3772059A US3772059DA US3772059A US 3772059 A US3772059 A US 3772059A US 3772059D A US3772059D A US 3772059DA US 3772059 A US3772059 A US 3772059A
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inorganic salt
solution
polyurethane
film
acid
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T Shikada
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Kanegafuchi Spinning Co Ltd
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Kanegafuchi Spinning Co Ltd
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    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
    • D06N3/00—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof
    • D06N3/0043—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof characterised by their foraminous structure; Characteristics of the foamed layer or of cellular layers
    • D06N3/0052—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof characterised by their foraminous structure; Characteristics of the foamed layer or of cellular layers obtained by leaching out of a compound, e.g. water soluble salts, fibres or fillers; obtained by freezing or sublimation; obtained by eliminating drops of sublimable fluid
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/26—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof by elimination of a solid phase from a macromolecular composition or article, e.g. leaching out
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
    • D06N3/00—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof
    • D06N3/12—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof with macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. gelatine proteins
    • D06N3/14—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof with macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. gelatine proteins with polyurethanes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/249921—Web or sheet containing structurally defined element or component
    • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
    • Y10T428/249978—Voids specified as micro

Definitions

  • ABSTRACT A method for producing a microporous sheet material having excellent abrasion resistance and 0 F A l t [3 1 orelgn pp [ca Pnonty Data moisture-permeability useful for artificial leathers Apr. 13, 1970 Japan wherein numerous bead like Spherical ro pores are arranged contiguously at barrier intervals in [52] Cl 117,63 117/1355 7/161 the interior of the microporous layer is proposed.
  • microporous sheet may be further ubjected to 3,387,989 6/1968 1 264/49 or grinding to produce a suede-like sheet material, if 3,524,753 8/1970 Sharp 1 117/11 required 3,483,015 12/1969 Fukashima et al ll7/l35.5 3,486,968 12/1969 Mater 117/1355 8 Claims, 2 Drawing Figures JJN V13] 7138/ WAVE LENGTH METHOD FOR PRODUCING MICROPOROUS SHEET MATERIAL
  • This invention relates to a novel and improved method for producing a microporous structure useful for artificial leather, more particularly, a microporous sheet material comprising predominantly a polyurethane elastomer which has deep color shade, light weight and excellent flexibility, abrasion resistance and moisture-permeability.
  • the desirable room temperature during the coating operation with a polyurethane solution was 21C and the desirable relative hymidity was 20 percent and that a higher humidity will cause faster coagulation and must be avoided in order to produce a desirable cellular structure.
  • the porous layer contains at least 50 percent by volume of conical pores, each of which diameter becomes larger from the top surface to the bottom surface of the layer.
  • microporous sheet is formed of so-called spongecake-like porous structure wherein innumerable spherical pores are arranged randomly from the surface to the interior of the layer, so that it is inferior in abrasion resistance and impact resistance. Therefore, when the porous sheet is further subjected to buffing to produce a suede-like material, it is rather difficult to regulate the buffing amount and to perform the smooth buffing operation.
  • the abovementioned porous sheet contains numerous h0neycomb-like pores from the inner layer to the bottom layer, so that when a suede-like sheet material is formed by buffing the top of the porous layer, the colour tone of the resulting material may be changed or be dull or dead by random reflection of light owing to difference in porous structure between its top surface layer and bottom layer.
  • the above cited method has such a drawback that when the amount of higher aliphatic carboxylic acid exceeds 30 percent by weight, the coagulation rate is too low and the moisture-permeability of the resulted product is inferior, and further when the said amount exceeds 50 percent by weight, non-porous film is formed or in the worst case, film is not formed.
  • the present invention has been accomplished to improve or solve the prior art defects or problems as mentioned above in the formation of a microporous sheet material, by employing as a coating solution a polymer solution predominantly comprising a polyurethane containing a specified amount of a mixture of a specified water-soluble inorganic salt and a specified higher aliphatic carboxylic acid, as mentioned hereinafter, and by coagulating the coated material in water or an aqueous solution of a specified inorganic salt same as above whereby a microporous sheet having a unique structure different from the above-mentioned known structures is formed due to a synergistic action of said inorganic salt and said higher aliphatic carboxylic acid and as a result, its abrasion resistance and moisturepermeability are remarkably improved co operatively.
  • the primary object of the invention is to provide a method for producing a smooth leather-like or suedelike microporous sheet material which is excellent in abrasion resistance, impact resistance, moisture permeability and color shade when colored.
  • the secondary object of the invention is to provide a method for producing an improved smooth leather like or suede-like, microporous sheet material easily and advantageously on industrial scale.
  • a method of producing a smooth leather-like microporous sheet material which comprises coating at least one surface of a fibrous base material or a plate for film making (substrate) with a mixture of solution of a polymer predominantly comprising a polyurethane in a watermiscible organic solvent, 100 to 500 percent by weight based on the weight of the polyurethane of particles of at least one inorganic salt selected from the group consisting of sodium sulphate, sodium chloride, potassium chloride and potassium sulphate and 35 to 100 percent by weight based on the weight of the polyurethane of at least one higher aliphatic carboxylic acid selected from the group consisting of stearic acid, palmitic acid and myristic acid, in a pellicle form, whereafter immersing the coated material in water or an aqueous solution of the said inorganic salt to coagulate the polymer and subsequently washing the coagulated matter with water and drying it thereby forming a micropo
  • the polyurethane to be used in the present invention may be any conventionally used as a polyurethane elastomer.
  • an organic diisocyanate and a polyalkylene ether glycol or a polyester having terminal hydroxyl groups are reacted with each other to produce a prepolymer and the prepolymer is subjected to a chain-extending reaction with a chain-extender such as a diamine, die] or polyol to form a linear polyurethane elastorner.
  • organic diisocyanates are exemplidied by aromatic, aliphatic or alicyclic diisocyanates or a mixture thereof, such as, for example, toluylene-2,6-diisocyanate, toluylene-2,4-diisocyanate, diphenylmethane-4 ,4 diisocyanate, 1,5-naphthylene cliisocyanate, hexamethylene diisocyanate or para-xylylene diisocyanate.
  • aromatic, aliphatic or alicyclic diisocyanates or a mixture thereof such as, for example, toluylene-2,6-diisocyanate, toluylene-2,4-diisocyanate, diphenylmethane-4 ,4 diisocyanate, 1,5-naphthylene cliisocyanate, hexamethylene diisocyanate or para-xylylene diisocyanate.
  • polyalkylene ether glycols examples include polyethylene ether glycol, poiypropylene ether glycol, polytetramethylene ether glycol or polyhexamethylene ether glycol or a copolymer or mixture thereof.
  • Polyols such as glycerin or trimethylol propane may also be used.
  • the polyesters which may be used in the production of a polyurethane elastorner include polycondensation products of organic acids and glycols.
  • Preferable glycol may be a polyalkylene glycol such as ethylene glycol, propylene glycol, tetramethylene glycol or hexamethylene glycol; a cyclic glycol such as cyclohexane diol; or an aromatic glycol such as xylylene glycol.
  • a polyalkylene glycol such as ethylene glycol, propylene glycol, tetramethylene glycol or hexamethylene glycol
  • a cyclic glycol such as cyclohexane diol
  • aromatic glycol such as xylylene glycol
  • succinic acid adipic acid, sebacic acid or terephthlic acid.
  • the polyester having terminal hydroxyl groups may be obtained by ringopening polymerization of a lactone in the presence of a small amount of a glycol or by polycondensation reaction of an excess diol and a dicarboxylic acid.
  • an average molecular weight of the polyester is about 500 to 3,000.
  • the lactone there may be mentioned, for example, delta-valerolactone, gammabutyrolactone and epsilon-caprolactone.
  • chain extender there may be mentioned diamine such as hydrazine, ethylene diamine or methylene diorthochloraniline.
  • a catalyst there may be employed, for example triethylamine, triethylene diamine, N-ethyl morpholine, dibutyl-tin-dilaurate or cobalt naphthenate.
  • the polyurethane thus prepared is dissolved in a water-miscible organic solvent to prepare a coating solution.
  • a small amount of other film forming polymer(s) soluble in said solvent for example, vinylic homopolymer or copolymer such as polyvinyl chloride, polyvinyl alcohol, polyacrylonitrile, polyacrylic ester or polyacrylic acid may be added to the polyurethane solution.
  • the solvent for polyurethane should be extractable with water, an alcohol or an aqueous solution of said inorganic salt. Therefore, a watermiscible organic solvent is used.
  • a solvent is exemplified by N,N'-dimethylformamide, dimethylsulfoxide, tetrahydrofuran, tetramethylurea, N,N'- dimethylacetamide, dioxane or butylcarbinol and may be used alone or in combination.
  • the most preferable solvent is N,N'-dimethylformamide.
  • ketones e.g., acetone, methylethylketoneetc.
  • a diluent in such a range that coagulation of the polymer may not be caused.
  • the polyurethane solution to be used in the present invention is a viscous solution containing homogeneously the above-mentioned polyurethane elastorner, fine particles of said inorganic salt and said higher aliphatic carboxylic acid and, if desired, the solution may further contain a coloring agent (dyestuff or pigment), light stabilizer, antistatic agent, dispersing agent such as metal soaps or surfactants, reinforcing agent (e.g., talc) and any other additive.
  • a coloring agent diestuff or pigment
  • light stabilizer light stabilizer
  • antistatic agent antistatic agent
  • dispersing agent such as metal soaps or surfactants
  • reinforcing agent e.g., talc
  • the coating polymer solution may be prepared by dissolving the polyurethane elastorner in said organic solvent and then admixing fine particles of said inorganic salt and said higher aliphatic earboxylic acid, along with other additive, if required, to the solution or by dissolving directly a mixture of the polyurethane elastorner, said inorganic salt and said higher aliphatic carboxylic acid and if required, an additive in the organic solvent.
  • the amount of the polyurethane elastorner to be contained in said solution may vary depending on the polymerization degree and chemical structure.
  • the concentration of the polyurethane in said solution is preferably within such a range that the solution as added with a required amount of said inorganic salt and said higher aliphatic carboxylic acid may remain in the form ofa solution (i.e., remain stable) for a long period of time at a temperature not exceeding 45 C and may be adjustable to a viscosity of 10,000 to 150,000 cps. under which the solution can be readily applied onto a substrate or base material.
  • the amount of the polyurethane elastomer is suitably 5 to 20 percent by weight, preferably 7.5 to percent by weight based on the weight of the coating solution. If below 5 percent by weight, the coagulating velocity will be unduly low and the properties or performances of the resulting film will be likely to deteriorate. In case of above percent by weight, the viscosity will be so high that the coating operation will be difficult and the quality of the resulting film will also be likely to deteriorate.
  • the coating solution of the present invention thus prepared is highly storage-stable and may be employed immediately after the preparation or after preserving for a long period of time without degrading performances of the resulting coagulated microporous sheet.
  • the coating solution is a polyurethane solution containing solely a higher aliphatic carboxylic acid
  • disadvantages or drawbacks can be completely eliminatd by the coexistence of an inorganic salt and a higher aliphatic carboxylic acid as specified above.
  • the amounts of said inorganic salt and said higher aliphatic carboxylic acid to be added to the polymer solution vary depending on the concentration of the polyurethane elastomer in the coating solution and also the nature and concentration of the said salt in the coagulating bath, but is generally in the ranges of 100 to 500 percent by weight and 35 to 100 percent by weight, respectively, based on the polyurethane elastomer. More preferably, the former is in a range of 150 to 400 percent by weight and the latter, in a range of 55 to 80 percent by weight based on the polyurethane elastomer.
  • the amount of said inorganic salt is less than 100 percent by weight and the amount of said higher aliphatic carboxylic acid is less than 35 percent by weight, the properties of the resulting film will be deteriorated since conical macro-pores will be formed in the interior of the resulting film and the color shade will be not clear when a coloring agent is mixed therewith. If the amount of said inorganic salt is less than [00 percent by weight and the amount of said higher aliphatic carboxylic acid is more than 100 percent by weight, the coagulation velocity of the coating solution will be remarkably low and the resulting film will be remarkably degraded since irregular crack-like pores will be formed in the interior of the film.
  • the amount of said inorganic salt is more than 500 percent by weight and the amount of said higher aliphatic carboxylic acid is less than 35 percent by weight, numerous spongecake-like spherical pores will be formed in the interior of the resulting film and properties (e.g., abrasion resistance) of the film will be deteriorated.
  • properties e.g., abrasion resistance
  • the top surface of the resulting film is ground or buffed to form a suede leather-like sheet, the buffing operation and the control of buff-off amount will be difficult.
  • a coloring agent is compounded, the tone of the colored film will be dull or dead.
  • the amount of said inorganic salt is more than 500 percent by weight and the amount of said higher aliphatic carboxylic acid is more than 100 percent by weight, the coagulation velocity will be remarkably low, and numerous spongecake-like spherical pores and irregular crack-like pores will be generated in the interior of the resulting film so that the properties such as abrasion resistance or strength of the film will be highly degraded.
  • the inorganic salt which is incorporated in the polyurethane elastomer solution is selected from the group consisting of sodium chloride, potassium chloride, sodium sulphate and potassium sulphate, and may be used alone or in combination. Since the said inorganic salts are non-hygroscopic but easily soluble in water, they can be readily dissolved and removed in the coagulating bath or water leaching bath in the subsequent step. When using, a required amount of said inorganic salt is added in the form of dried and finely divided particles to the polyurethane solution with other additives and is mixed sufficiently until uniformly dispersed.
  • the particle size of said inorganic salt is suitably not more than microns, preferably not more than 50 microns. When the particle size of said inorganic salt is larger, it is difficult to maintain homogeneity of the polyurethane solution for a long period of time and also difficult to obtain a uniform microporous sheet.
  • the higher aliphatic carboxylic acid to be added together with said inorganic salt to the polyurethane solution is selected from the group consisting of myristic acid, palmitic acid and stearic acid and may be used alone or in combination.
  • a required amount of said higher aliphatic carboxylic acid in the form of powders or flakes is added together with other additives to the polyurethane solution and is mixed thoroughly until a uniform solution is obtained.
  • the inorganic salt, higher aliphatic carboxylic acid and other additives such as coloring agent may be compounded in the polyurethane elastomer solution with a kneader, mixing roll or other mixer.
  • the best results are attained by the combination of sodium chloride and stearic acid or by the combination of sodium sulphate and stearic acid, among various combinations of said inorganic salt and said higher aliphatic carboxylic acid.
  • the polyurethane elastomer coating solution thus prepared is, before being led into a coagulating bath,
  • the coating solution used in the present invention does not contain a non-solvent such as water or a hygroscopic inorganic salt such as calcium chloride, calcium nitrate and the like, elevation of its viscosity and gelation will not occur even if it absorbs moreor less water or moisture during the coating step and the coagulating step. Therefore, the coating operation can be readily conducted even in a high humid atmosphere and the coagulation in a coagulating bath is smoothly performed. Thus an excellent microporous sheet may be resulted.
  • a non-solvent such as water or a hygroscopic inorganic salt such as calcium chloride, calcium nitrate and the like
  • the coagulating bath of this invention there may be used water or an aqueous solution of at least one inorganic salt selected from the group consisting of sodium sulphate, sodium chloride, potassium sulphate and potassium chloride.
  • the concentration of an aqueous solution of said inorganic salt in the coagulating bath may vary depending on the kind of the salt, the amount of the inorganic salt in the polyurethane elastomer coating solution and the concentration of the polyurethane elastomer solution, but is generally suitably below the amount (by weight) corresponding to two-thirds, preferably below one-third and most preferably below one-fifth the concentration of the saturated aqueous solution. At such high concentration as above two-thirds the saturation, the coagulating velocity of the polyurethane solution film will be reduced so much that the resulting coagulating film will form a too compact structure and therefore it will be difficult to obtain a desired porous sheet.
  • the coagulating bath temperature may be suitably in a range of to 50C, preferably to 40Cv
  • Advantages in the use of the coagulating bath of the present invention are that water and said inorganic salt in the bath are inexpensive and economical and even if much amount of N,N'-dimethylformamide is accumulated in the coagulating bath during its successive use for a long period of time, coagulation may be normally performed by a special coagulating (regenerating) action of the inorganic salts in the coagulating bath as well as in the polyurethane elastomer solution whereby a microporous sheet having excellent performances can be formed.
  • the said inorganic salt in the coagulating bath is chemically inert to such a solvent for polyurethane elastomer as N,N'-dimethylformamide so that there is no danger of inducing a hydrolysis as in the case of an acidic salt and therefore the solvent can be recovered readily and smoothly.
  • the higher aliphatic carboxylic acid in the coated film is extricated from the film and floats over the surface of the coagulating bath so that it can be easily separated.
  • the coagulating bath temperature is near standard or room temperature.
  • the temperature may be varied so that the coagulating activity of the salt solution may be varied.
  • the temperature range showing a favorable coagulation and regeneration is sufficiently wide so that there would be no difficulty in selecting bath temperature.
  • the base material or, substrate or plate for film making coated with the coating solution in a required thickness is immersed in the coagulating bath i.e., water or an aqueous solution of said inorganic salt which has been prepared under appropriate conditions as described above, for a specified period of time to coagulate and regenerate the polyurethane elastomer.
  • the coagulating bath i.e., water or an aqueous solution of said inorganic salt which has been prepared under appropriate conditions as described above, for a specified period of time to coagulate and regenerate the polyurethane elastomer.
  • the coagulated film of polyurethane elastomer is washed with water to leach out and thoroughly remove the inorganic salt, higher aliphatic carboxylic acid and water-miscible organic solvent that have been still remained in the said film, and then dried.
  • the coating polymer solution When the coating polymer solution is applied onto a film-making plate such as a glass plate, metal plate or plastic plate and is coagulated and regenerated thereon, the resulting film having a porous structure will be formed as bonded and laminated on said plate. Therefore, it is washed with water and dried and then the film is peeled off the plate.
  • the thus-obtained film is tough and light, and remarkably excellent in the abrasion resistance, impact resistance, softness and moisture-permeability.
  • the coating polymer solution is applied to a fibrous or other base material suitable for synthetic leathers, such as a woven fabric, knitted fabric, nonwoven fabric, film, sponge or paper and coagulated thereon, the resulting film having a microporous structure is formed in an adhered and laminated state on said base material, and then washed with water and dried.
  • a fibrous or other base material suitable for synthetic leathers such as a woven fabric, knitted fabric, nonwoven fabric, film, sponge or paper and coagulated thereon
  • the resulting film having a microporous structure is formed in an adhered and laminated state on said base material, and then washed with water and dried.
  • the microporous sheet having excellent toughness, softness, abrasion resistance, impact resistance and moisture-permeability can be obtained.
  • the resulting product may be employed as an artificial leather.
  • microporous sheet material exhibits excellent perform ances i.e., light weight, good toughness, abrasion resistance, moisture-permeability and softness.
  • the resulted microporous sheet is superior in toughness, abrasion resistance and impact resistance since no spongecake-like microporous structure is formed in the wear was determined in accordance with the method of JIS--L104859, and is expressed by friction cycle (frequency) till the microporous film is completely worn out by frictioning.
  • FIG. 1 and FIG. 2 are graphs 20 sequently, the fabric with the film formed thereon was showing such a deep, clear color tone of the invention. washed with water at 50C for 60 minutes to remove The microporous sheet obtained in accordance with the N,N'-dimethylformamide, inorganic salt and higher the present invention is superior in abrasion resistance aliphatic carboxylic acid remaining in the film and and impact resistance and remarkably superior in thereafter was air-dried at 100C for 10 minutes. moisture-permeability to those of prior art micropo- The thus-obtained regenerated polyurethane film rous sheet as described in British Patent No.
  • 1,129,122 was observed microscopically of its cross-sectional wherein a specifed higher aliphatic carboxylic acid is structure and determined with respect to its solely incorporated in a polyurethane solution and moisture-permeability, surface wear and specific gravlong, crack-like micropores are formed. In the present ity. The results are shown in Table 1.
  • the microporous film obtained from the of the higher aliphatic carboxylic acid is incorporated coating solution containing 100 to 500 parts of the inin the polyurethane solution, neither the coagulating organic salt and to 100 parts of the higher aliphatic velocity becomes low nor non-porous film is formed, as carboxylic acid based on 100 parts of polyurethane has in the case of British Patent No. 1,129,122 as above. a microporous structure of numerous, so-called bead- These eminent differences in effect between the pres- 35 like connected spherical micropores wherein homogeent invention and the prior arts are ascribed to a synerneous spherical micropores with ca.
  • the microporous sheet material obtained by the formed film has remarkably superior moisture-permeamethod of the invention is useful for upholsteries, room bility, abrasion resistance and softness. Particularly, interior decorations, packages, handbags, gloves, above all, the film from the coating solution containing boots, shoes and clothes.
  • the suede-like sheet is useful 150 to 400 parts of the inorganic salt and to parts for shoe uppers, jackets and other coats, decorative of the higher aliphatic carboxylic acid is more excellent leather liners, suitcases and covers of tables and rolls. 45 in these performances.
  • Example 1 The procedure for Example 1 was exactly duplicated, except that water bath at 30C was substitued for the aqueous solution of the inorganic salt.
  • the results of this example are a little of 60,000 P at The coating Solution was pp inferior in moisture-permeability and abrasion resisy a coating Toner to a Polyester fiber non-Woven fabric tance as compared i h Example 1 wherein the aque having a thickness of 0.6 mm in a thickness of 0.8 mm ous solution of the inorganic salt is used as a coagulatand the coated fabric was introduced at an angle of ing bath into a water bath at C for 20 minutes to coagulate TABLE 2 Additive in coating solution Performances of film Moisture- Aliphatic Heme Surface carboxylic Interior structure of film; cross-sectional structure Sp. gr.
  • the resulted suede-like sheet has a density of 0.49 to 0.55 g/cm and exhibits excellent abrasion resistance and moisture-permeability as shown in Table 3 given below.
  • the colour shade was determined by measuring surface reflectance with an autographical spectrophotometer (made by General Electric Co.) and the results are shown in the accompanying FIGS. 1 and 2.
  • Comparative examples were also conducted in a similar manner to the afore-mentioned procedure except that a sole polyurethane solution (with no additive), a polyurethane solution containing solely the inorganic salt or a polyurethane solution solely containing the higher aliphatic carboxylic acid was used as a coating solution instead of the polyurethane solution containlating bath consisting of water or an aqueous solution of sodium chloride as shown in Table 4 as given below at C for 30 minutes to coagulate and regnerate the polymer.
  • a sole polyurethane solution with no additive
  • a polyurethane solution containing solely the inorganic salt or a polyurethane solution solely containing the higher aliphatic carboxylic acid was used as a coating solution instead of the polyurethane solution containlating bath consisting of water or an aqueous solution of sodium chloride as shown in Table 4 as given below at C for 30 minutes to coagulate and regnerate the polymer.
  • Comparative films were also prepared in a similar manner except that sole sodium chloride or sole stearic acid was used as an additive in the coating solution instead of the combination of sodium chloride and stearic acid.
  • EXAMPLE 4 A coating solution having a viscosity of 60,000 cps at 25C was prepared by admixing 500 parts of sodium chloride having particle sizes of ca. 20 to 40 microns, 150 parts of stearic acid and 50 parts of carbon black with a 25 percent N,N-di-methy1formamide solution of ester type polyurethane elastomer same as used in Example l, and applied onto a glass plate in a thickness of 1.2 mm.
  • the coated plate was immersed in a coagu- EXAMPLE 5
  • a 25 percent N,N'-dimethylformamide solution of ester type polyurethane elastomer as used in Example 1 were admixed 200 parts of N,N'-dimethylformamide, 500 parts of anhydrous sodium sulphate, parts of stearic acid and 50 parts of channel carbon black to prepare a coating solution having a viscosity of 70,000 cps at 25C.
  • the coating solution was applied onto a cotton satin fabric in a thickness of 0.4 mm and the fabric was immersed in water at 30C for 10 minutes to coagulate and regenerate the polymer.
  • the thus-obtained microporous sheet has a moisture-permeability of 8.5 mg/cmlhr and a surface wear of 2,500 cycles, and is useful for manufacture of shoes and bags.
  • a microporous sheet was also produced in a manner similar to the procedure described above except that a 5 percent aqueous solution of sodium sulphate was substituted for the water as a coagulating bath. The resulted sheet exhibits a moisture-permeability of 12.0 mg/cmlhr and a surface wear of 2,600 cycles, which results are improved over the above sheet.
  • Comparative examples were repeated in an identical manner to the procedure as above except that sole anhydrous sodium sulphate or sole stearic acid was used as an additive in the coating solution instead of the combination of anhydrous sodium sulphate and stearic acid, and respective sheets were prepared.
  • the former sheet has a moisture-permeability of 6.0 mg/cmlhr, while the latter is of substantially nonporous film and has a moisture-permeability of 0.4 mg/cmlhr and a surface wear of 3,400 frequencys.
  • EXAMPLE 6 To 1,000 parts of a 25 percent N,N'-dimethylformamide solution of ester type polyurethane as used in Example l were admixed 150 parts of sodium chloride, 138 parts of stearic acid, 50 parts of channel carbon black and 300 parts of N,N'-dimethylformamide to prepare a coating solution having a viscosity of 70,000 cps at 25C. The coating solution was applied onto a cotton stain fabric in a thickness of 0.7 mm and the fabric was immersed in hot water at 30C for 10 minutes to coagulate and regenerate the polymer. Subsequently after washing and leaching with hot water at 50C for 30 minutes, the fabric with coagulated film was dried in a hot air dryer at 110C.
  • the resulted microporous sheet was buffed and ground with a sand paper in a depth of 0.2 mm from its surface.
  • a deep black suede-like sheet wherein numerous spherical micropores with 30 to 50 microns in sizes bead-likely linked with each other were arranged.
  • the suede-like sheet has a strength of 24 Kg/cm, an elongation at break of 22 percent, a moisture-permeability of 12.3 mg/cmlhr and a surface wear of 2,100 cycles, and is useful for shoes, bags, upholsteries, etc.
  • microporous sheet was also prepared in an identical manner as the procedure was described above except that a percent aqueous solution of sodium chloride was substituted for the water as a coagulating bath, which had a moisture-permeability of 15.0 mg/cm lhr and a surface wear of 2,600 cycles.
  • the comparative sheets were prepared in a similar manner to this example except that sole sodium chloride or sole stearic acid was substituted for the combination of sodium chloride and stearic acid as an additive in a coating solution.
  • the former sheet has a moisture-permeability of 9.1 mglcm lhr and a surface wear of 550 cycles, while the latter is substantially nonporous and has a moisture-permeability of 0.4 mg/cm /hr. Even if buffed or ground, the latter is not finished into a suedelike sheet.
  • EXAMPLE 7 A polyurethane elastomer coating solution having a viscosity of 60,000 cps at 25C was prepared by admixing 1,200 parts of anhydrous sodium sulphate, 165 parts of stearic acid and 50 parts of pigment, C.l.Solvent Blue 11 with 1,000 parts of a 30 percent N,N'-dimethylformamide solution of ester type polyurethane, and applied onto a napped surface of flannel fabric in a thickness of 0.7 mm. Thereafter the fabric was immersed in a coagulating bath of a 5 percent aqueous solution of sodium sulphate at 30C for minutes, treated with hot water at 50C for 30 minutes and then dried in a hot air dryer at 110C. The thusobtained sheet has a moisture-permeability of 11.5 mg/cmlhr and a surface wear of 3,150 cycles. 1t exhibits a deep blue color shade and is highly useful for clothings, bags, shoes, interior decorations, etc.
  • control sheet was prepared in a similar manner to the procedure as described above except that a polyurethane coating solution containing solely sodium sulphate was substituted for the above-described coating solution, and the resulted sheet had a moisture-permeability of 5.6 mg/cmlhr and a surface wear of 550 cycles. Also control sheet was prepared similarly from a polyurethane elastomer coating solution containing a solely stearic acid, and the resulted sheet was substantially non-porous and had a moisture-permeability of 0.3 mglcm lhr.
  • EXAMPLE 8 A suede-like sheet was prepared by grinding or buffing the surface of the microporous sheet as obtained in Example 7 with a sand paper in a depth of 0.2 mm.
  • the resulted suede-like sheet is of numerous micropores having diameters of 20 to 40 microns, and has a moisture-permeability of 15.8 mg/cm /hr, a surface wear of 2,300 cycles and density of 0.43 g/cm.
  • a suede-like sheet was prepared from the corresponding control sheet in Example 7 obtained from the coating solution containing solely sodium sulphate.
  • the resulted suedelike sheet has a moisture-permeability of 10.5 mglcm lhr and surface wear of 350 cycles.
  • the other control sheet obtained from the coating solution containing solely stearic acid is substantially non-porous and a suede-like sheet can not be formed, even if buffed.
  • a method for producing a microporous sheet material having excellent abrasion resistance, moisture permeability, color shade and softness which comprises the steps of:
  • a liquid coagulating bath selected from the group consisting of water and an aqueous solution of said inorganic salt having a salt concentration of less than twothirds the concentration of a saturated aqueous solution of said salt, said bath having a temperature in the range of from 5 to 50C;
  • liquid coating material contains inorganic salt in an amount in a range of to 400 percent by weight based on the weight of the polyurethane.
  • a method according to claim 1 wherein the inorganic salt in the coating solution is the same as that in the coagulating bath 7.
  • a method according to claim 1 wherein said polymer consists essentially of a polyester polyurethane elastomer.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Dispersion Chemistry (AREA)
  • Materials Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
  • Synthetic Leather, Interior Materials Or Flexible Sheet Materials (AREA)
US3772059D 1970-04-13 1971-04-05 Method for producing microporous sheet material Expired - Lifetime US3772059A (en)

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CA (1) CA935614A (en, 2012)
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FR (1) FR2092034B1 (en, 2012)
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Cited By (17)

* Cited by examiner, † Cited by third party
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US3949123A (en) * 1972-12-08 1976-04-06 Uniroyal Inc. Coated fabric having suede-like surface
US4148734A (en) * 1974-12-21 1979-04-10 Chemie-Anlagenbau Bischofsheim Gmbh Filter material and process for producing same
US4171391A (en) * 1978-09-07 1979-10-16 Wilmington Chemical Corporation Method of preparing composite sheet material
US4547423A (en) * 1982-07-15 1985-10-15 Sony Corporation Textile for clothes
US4554198A (en) * 1982-01-14 1985-11-19 Bluecher Hubert Waterproof and air-tight, moisture-conducting textile material
US5716680A (en) * 1995-03-14 1998-02-10 The Dow Chemical Company Solventless process for forming thin, durable coatings of perfluorocarbon ionomers on various polymeric materials
US5718947A (en) * 1995-03-14 1998-02-17 The Dow Chemicalcompany Processes for forming thin, durable coatings of cation-containing polymers on selected substrates
US5746954A (en) * 1995-09-07 1998-05-05 The Dow Chemical Company Processes for forming thin, durable coatings of perfluorocarbon ionomers on various substrate materials
US20040121113A1 (en) * 2002-12-20 2004-06-24 Mobley Larry Wayne Process to make synthetic leather and synthetic leather made therefrom
US20050170189A1 (en) * 2004-02-03 2005-08-04 Bayer Materialscience Ag Composite elements made from polyurethane materials having surfaces consisting of thermoplastic or metallic layers and a process for their production
WO2008077786A1 (de) * 2006-12-22 2008-07-03 Basf Se Verfahren zur herstellung von beschichteten textilien, insbesondere kunstleder
US20100247778A1 (en) * 2009-03-30 2010-09-30 Xiaolin Sha Process for producing polyurethane coated gloves
WO2011076971A3 (es) * 2009-12-23 2011-10-06 Fundacion Inasmet Artículo de peek poroso como implante
US20120234479A1 (en) * 2006-02-20 2012-09-20 Chung-Ching Feng Composite coating material and the production method of the same
WO2016174418A1 (en) * 2015-04-27 2016-11-03 Midas Safety Innovations Limited Polyurethane coated fabric
EP3135809A1 (en) * 2015-08-31 2017-03-01 Dong Woo Alt Co., Ltd Polyurethane synthetic leather and polyurethne film comprising sucrose and method for preparing the same
CN113417150A (zh) * 2021-07-08 2021-09-21 江苏聚杰微纤科技集团股份有限公司 一种高固含环保pu绒面革及其制备方法

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FR2530189B1 (fr) * 1982-07-16 1988-08-26 Fujikura Rubber Ltd Procede de fabrication d'une couche compressible et d'un blanchet pour operations d'impression
JPS5996118A (ja) * 1982-11-24 1984-06-02 Toray Ind Inc ポリウレタン成形物
JPS62197183A (ja) * 1986-02-24 1987-08-31 Nisshinbo Ind Inc 表面多孔性プラスチツクシ−トの製造方法
CN115262238B (zh) * 2022-09-27 2023-01-03 吴江市汉塔纺织整理有限公司 一种防水透气聚氨酯涂层及其海岛湿法制备方法

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US3296016A (en) * 1963-10-31 1967-01-03 Goodrich Co B F Production of microporous coating on substrate
US3387989A (en) * 1965-09-20 1968-06-11 Reeves Bros Inc Simulated leather products
US3483015A (en) * 1965-02-03 1969-12-09 Kuraray Co Method for production of poromeric fibrous sheet materials
US3486968A (en) * 1967-10-12 1969-12-30 Reeves Bros Inc Microporous polyurethane coatings and films
US3524753A (en) * 1963-11-25 1970-08-18 Porvair Ltd Method of making a microporous film
US3582393A (en) * 1967-11-18 1971-06-01 Kanegafuchi Spinning Co Ltd Method of producing porous sheet material
US3595685A (en) * 1968-12-23 1971-07-27 Nippon Cloth Industry Co Ltd Method for preparing suede-like material

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GB1122804A (en) * 1964-08-13 1968-08-07 Porous Plastics Ltd Improvements relating to the production of microporous polymeric plastics materials
FR1466907A (fr) * 1965-02-03 1967-01-20 Kurashiki Rayon Co Procédé de fabrication de matériaux en feuilles souples et résistantes et les produits ainsi obtenus
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US3275468A (en) * 1966-09-27 Tomoo aoki
US3000757A (en) * 1957-01-28 1961-09-19 Du Pont Process for coating substrates with a vapor permeable polymeric coating
US3284274A (en) * 1962-08-13 1966-11-08 Du Pont Cellular polymeric sheet material and method of making same
US3296016A (en) * 1963-10-31 1967-01-03 Goodrich Co B F Production of microporous coating on substrate
US3524753A (en) * 1963-11-25 1970-08-18 Porvair Ltd Method of making a microporous film
US3483015A (en) * 1965-02-03 1969-12-09 Kuraray Co Method for production of poromeric fibrous sheet materials
US3387989A (en) * 1965-09-20 1968-06-11 Reeves Bros Inc Simulated leather products
US3486968A (en) * 1967-10-12 1969-12-30 Reeves Bros Inc Microporous polyurethane coatings and films
US3582393A (en) * 1967-11-18 1971-06-01 Kanegafuchi Spinning Co Ltd Method of producing porous sheet material
US3595685A (en) * 1968-12-23 1971-07-27 Nippon Cloth Industry Co Ltd Method for preparing suede-like material

Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3949123A (en) * 1972-12-08 1976-04-06 Uniroyal Inc. Coated fabric having suede-like surface
US4148734A (en) * 1974-12-21 1979-04-10 Chemie-Anlagenbau Bischofsheim Gmbh Filter material and process for producing same
US4171391A (en) * 1978-09-07 1979-10-16 Wilmington Chemical Corporation Method of preparing composite sheet material
US4554198A (en) * 1982-01-14 1985-11-19 Bluecher Hubert Waterproof and air-tight, moisture-conducting textile material
US4547423A (en) * 1982-07-15 1985-10-15 Sony Corporation Textile for clothes
US5718947A (en) * 1995-03-14 1998-02-17 The Dow Chemicalcompany Processes for forming thin, durable coatings of cation-containing polymers on selected substrates
US5716680A (en) * 1995-03-14 1998-02-10 The Dow Chemical Company Solventless process for forming thin, durable coatings of perfluorocarbon ionomers on various polymeric materials
US5746954A (en) * 1995-09-07 1998-05-05 The Dow Chemical Company Processes for forming thin, durable coatings of perfluorocarbon ionomers on various substrate materials
US5993907A (en) * 1995-09-07 1999-11-30 The Dow Chemical Company Processes for forming thin, durable coatings of perfluorocarbon ionomers on various substrate materials
US20040121113A1 (en) * 2002-12-20 2004-06-24 Mobley Larry Wayne Process to make synthetic leather and synthetic leather made therefrom
US7306825B2 (en) * 2002-12-20 2007-12-11 Dow Global Technologies Inc. Process to make synthetic leather and synthetic leather made therefrom
US7638197B2 (en) * 2004-02-03 2009-12-29 Bayer Materialscience Ag Composite elements made from polyurethane materials having surfaces consisting of thermoplastic or metallic layers and a process for their production
US20050170189A1 (en) * 2004-02-03 2005-08-04 Bayer Materialscience Ag Composite elements made from polyurethane materials having surfaces consisting of thermoplastic or metallic layers and a process for their production
US20120234479A1 (en) * 2006-02-20 2012-09-20 Chung-Ching Feng Composite coating material and the production method of the same
US20090311929A1 (en) * 2006-12-22 2009-12-17 Basf Se Method of producing coated textile, more particularly synthetic leathers
WO2008077786A1 (de) * 2006-12-22 2008-07-03 Basf Se Verfahren zur herstellung von beschichteten textilien, insbesondere kunstleder
US8449944B2 (en) 2006-12-22 2013-05-28 Basf Se Method of producing coated textile, more particularly synthetic leathers
US20100247778A1 (en) * 2009-03-30 2010-09-30 Xiaolin Sha Process for producing polyurethane coated gloves
US8241705B2 (en) * 2009-03-30 2012-08-14 Xiaolin Sha Process for producing polyurethane coated gloves
WO2011076971A3 (es) * 2009-12-23 2011-10-06 Fundacion Inasmet Artículo de peek poroso como implante
EP2338532A3 (en) * 2009-12-23 2013-03-20 Fundacion Inasmet Porous PEEK article as an implant
WO2016174418A1 (en) * 2015-04-27 2016-11-03 Midas Safety Innovations Limited Polyurethane coated fabric
US10662579B2 (en) 2015-04-27 2020-05-26 Midas Safety Innovations Limited Polyurethane coated fabric
EP3135809A1 (en) * 2015-08-31 2017-03-01 Dong Woo Alt Co., Ltd Polyurethane synthetic leather and polyurethne film comprising sucrose and method for preparing the same
CN106480747A (zh) * 2015-08-31 2017-03-08 东宇阿尔特有限公司 含有蔗糖的聚氨酯合成革和聚氨酯薄膜及其制造方法
CN113417150A (zh) * 2021-07-08 2021-09-21 江苏聚杰微纤科技集团股份有限公司 一种高固含环保pu绒面革及其制备方法

Also Published As

Publication number Publication date
DE2117350B2 (en, 2012) 1974-01-24
NL141940B (nl) 1974-04-16
JPS4819704B1 (en, 2012) 1973-06-15
CA935614A (en) 1973-10-23
FR2092034A1 (en, 2012) 1972-01-21
DE2117350C3 (de) 1978-12-14
GB1329499A (en) 1973-09-12
NL7104876A (en, 2012) 1971-10-15
FR2092034B1 (en, 2012) 1974-03-22
DE2117350A1 (en, 2012) 1971-10-28

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